U.S. patent application number 14/413326 was filed with the patent office on 2015-07-09 for media bed filters for filtering fine particles from a raw liquid flow and method of using the same.
The applicant listed for this patent is SONITEC-VORTISAND TECHNOLOGIES INC.. Invention is credited to Marco Bosisio, Alain Silverwood.
Application Number | 20150190738 14/413326 |
Document ID | / |
Family ID | 49913058 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150190738 |
Kind Code |
A1 |
Bosisio; Marco ; et
al. |
July 9, 2015 |
MEDIA BED FILTERS FOR FILTERING FINE PARTICLES FROM A RAW LIQUID
FLOW AND METHOD OF USING THE SAME
Abstract
The present document describes a media bed filter for filtering
fine particles from a raw liquid flow, the media bed filter
comprising: a tank having: a top portion; a bottom portion defining
a bottom surface for receiving a media bed, the media bed having a
supporting media to be disposed on the bottom surface and a
filtering media for covering the supporting media, the top portion
of the tank being above the filtering media of the media bed; a raw
liquid inlet in fluid communication with a nozzle configuration
located in the top portion of the tank for providing the raw liquid
flow in the tank in the form of a plurality of jets at a
directional velocity substantially equal or greater to a
disengagement velocity of the filtering media.
Inventors: |
Bosisio; Marco;
(Pierrefonds, CA) ; Silverwood; Alain;
(St-Eustache, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SONITEC-VORTISAND TECHNOLOGIES INC. |
St-Laurent |
|
CA |
|
|
Family ID: |
49913058 |
Appl. No.: |
14/413326 |
Filed: |
July 16, 2013 |
PCT Filed: |
July 16, 2013 |
PCT NO: |
PCT/CA2013/000648 |
371 Date: |
January 7, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61672098 |
Jul 16, 2012 |
|
|
|
Current U.S.
Class: |
210/807 ;
210/287 |
Current CPC
Class: |
B01D 24/14 20130101;
B01D 2024/145 20130101; B01D 24/105 20130101; C02F 2103/02
20130101; B01D 24/4678 20130101; C02F 1/001 20130101; B01D 24/40
20130101 |
International
Class: |
B01D 24/10 20060101
B01D024/10; B01D 24/40 20060101 B01D024/40 |
Claims
1. A media bed filter for filtering fine particles from a raw
liquid flow, the media bed filter comprising: a tank having: a top
portion; a bottom portion defining a bottom surface for receiving a
media bed, the media bed having a supporting media to be disposed
on the bottom surface and a filtering media for covering the
supporting media, the top portion of the tank being above the
filtering media of the media bed; a raw liquid inlet in fluid
communication with a nozzle configuration located in the top
portion of the tank for providing the raw liquid flow in the tank
in the form of a plurality of jets at a directional velocity
substantially equal or greater to a disengagement velocity of the
filtering media.
2. The media bed filter of claim 1, wherein the nozzle
configuration comprises a plurality of nozzles, each one of the
plurality of nozzles for providing the raw liquid flow in the tank
in the form of a respective one of the plurality of jets at the
directional velocity towards the filtering media.
3. The media bed filter of claim 2, wherein the plurality of
nozzles are oriented in opposite directions.
4. The media bed filter of claim 1, wherein the top portion of the
tank defines a top portion surface and further wherein the nozzle
configuration is oriented for providing the plurality of jets
towards the top portion surface of the tank, thereby providing the
raw liquid flow in the tank at a parallel velocity substantially
equal or greater to the disengagement velocity of the filtering
media.
5. The media bed filter of claim 4, wherein the nozzle
configuration is one of: located above the raw liquid inlet within
the top portion of the tank and located below the raw liquid inlet
within the top portion of the tank.
6. The media bed filter of claim 1, wherein the nozzle
configuration is oriented for providing the plurality of jets
perpendicularly towards the filtering media of the media bed.
7. The media bed filter of claim 6, further comprising a baffle
located in the top portion of the tank and between the nozzle
configuration and the filtering media.
8. The media bed filter of claim 7, wherein the baffle is located
substantially above the filtering media, thereby providing the raw
liquid flow in the tank at a parallel velocity substantially equal
or greater to the disengagement velocity of the filtering
media.
9. The media bed filter of claim 1, wherein the raw liquid inlet
comprises a plurality of raw liquid inlets, each one of the
plurality of raw liquid inlets being in fluid communication with a
respective nozzle configuration.
10. The media bed filter of claim 1, wherein the nozzle
configuration is one of: oriented in an upward direction for
providing the plurality of jets to enter the tank in an upwardly
direction and oriented in a downwardly direction for providing the
plurality of jets to enter the tank in a downwardly direction.
11. The media bed filter of claim 1, wherein the nozzle
configuration is oriented for providing the plurality of jets
horizontally towards the filtering media of the media bed, the
nozzle configuration being located in the top portion of the tank
at substantially the same level of the filtering media.
12. The media bed filter of claim 2, wherein each one of the
plurality of nozzles defines a shape comprising at least one of: an
elbow-like shape, a straight-like shape, a curved-like shape, a
regular polygonal-like shape, a segmented-like shape, an irregular
polygonal-like shape, a circular-like shape, an angular-like shape,
and any combination thereof.
13. The media bed filter of claim 1, further comprising a baffle
within the top portion of the tank for receiving the plurality of
jets, thereby providing the raw liquid flow in the tank at a
parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media.
14. The media bed filter of claim 13, wherein the baffle comprises
a plurality of baffles, each one of the plurality of baffles being
located substantially above the filtering media, parallel and
laterally distant from another one of the plurality of baffles.
15. The media bed filter of claim 14, wherein the plurality of
baffles comprises displaceable baffles.
16. A method for filtering fine particles from a raw liquid flow in
a tank supporting a filtering media, the tank having a top portion,
the method comprising the steps of: receiving the raw liquid flow
with fine particles; and providing the raw liquid flow in the top
portion of the tank in the form of a plurality of jets at a
directional velocity substantially equal or greater to a
disengagement velocity of the filtering media.
17. The method of claim 16, wherein the providing the raw liquid
flow in the top portion of the tank in the form of a plurality of
jets comprises providing the raw liquid flow in the top portion of
the tank in the form of a plurality of jets oriented in opposite
directions, thereby providing the raw liquid flow in the tank at a
parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media.
18. The method of claim 16, wherein the providing the raw liquid
flow in the top portion of the tank in the form of a plurality of
jets comprises providing the raw liquid flow in the top portion of
the tank in the form of a plurality of jets towards a top portion
surface of the tank, thereby providing the raw liquid flow in the
tank at a parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media.
19. The method of claim 16, wherein the providing the raw liquid
flow in the top portion of the tank in the form of a plurality of
jets comprises providing the plurality of jets perpendicularly
towards the filtering media of the media bed.
20. The method of claim 16, wherein the providing the raw liquid
flow in the top portion of the tank in the form of a plurality of
jets comprises providing the raw liquid flow in the top portion of
the tank in the form of a plurality of jets at substantially the
same level of the filtering media, thereby providing the raw liquid
flow in the tank at a parallel velocity substantially equal or
greater to the disengagement velocity of the filtering media.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. provisional patent
application 61/672,098 filed on Jul. 16, 2012.
BACKGROUND
[0002] (a) Field
[0003] The subject matter disclosed generally relates to filtering
apparatus and methods of using the same. More particularly, the
subject matter relates to media bed filters for filtering fine
particles from a raw liquid flow.
[0004] (b) Related Prior Art
[0005] Media bed filters work by providing the solid particles with
many opportunities to be captured on the surface and within a
filtering media bed. As fluid is evenly distributed at the top of
the filter, it gently flows through the porous sand (i.e.,
filtering media) along a tortuous route, the particles come close
and in contact with the media bed. They can be captured by one of
several mechanisms such as, direct collision, Van der Waals or
London force attraction, surface charge attraction, diffusion, and
the like.
[0006] In addition, solid particles can be prevented from being
captured by surface charge repulsion if the surface charge of the
filtering media is of the same sign (i.e., positive or negative) as
that of the particulate solid. Furthermore, it is possible to
dislodge captured solid particles although they may be re-captured
at a greater depth within the media bed.
[0007] Filtering media beds can be operated either with upward
flowing fluids or downward flowing fluids the latter being much
more usual. For downward flowing filtering media beds, the fluid
can flow under pressure or by gravity alone. Pressure media bed
filters tend to be used in industrial applications. Gravity fed
units are used in water purification especially in large
application such as drinking water.
[0008] Overall, there are several categories of filtering media
beds such as, without limitation, gravity media bed filters,
pressure media bed filters, upflow media bed filters, slow media
bed filters, multimedia bed filters and the like.
[0009] All of these apparatus and methods are used extensively in
the water industry throughout the world.
[0010] For example, water from cooling tower attracts and absorbs
most dirt and airborne on a continuous basis. The majority of
suspended solids in circulating cooling water loops are from about
0-5 micron in size, mainly because of chemical dispersing agents
that are designed to limit circulating (i.e., dust and minerals
kept in suspension by dispersing chemical agents) dirt from
agglomerating on heat exchange surfaces. Dirt does negatively
affect heat exchange surfaces and cooling tower fill efficiency.
Traditional filters, strainers and separators will not remove
significantly these very fine contaminants before they settle out
in low flow areas, clog strainers, nozzles, and bio-fouled heat
exchangers. Usually, most media bed filters of this kind are not
able to significantly retain suspended solid of less than 5 microns
in size. There is therefore a need to provide a media bed filter
designed to provide an improved filtration for fine particles down
to 0.5 microns. For example, a traditional multi-layers media bed
filter having 3 layers including garnet is able to filter particles
only down to 10 or 20 microns.
[0011] For example and referring now to Prior Art FIGS. 1A, 1B, 1C,
1D and 1E, there are shown traditional sand filters. These
traditional sand filters offer a plurality of disadvantages. One of
them is that, a slope is created by the raw liquid fluid entering
the tank. The prior art configuration will allow the raw liquid
flow to dig at one place only on the media bed. Thus, according to
the traditional media bed filter, only a portion of the media bed
is utilized as the filtering surface. One of the other
disadvantages is that traditional sand filters cannot be used at
greater flow rates. When using traditional sand filters, water
needs to enter the tank at a substantially small velocity and
cannot include many flow rate variations. Additionally, such
configurations proposed by traditional media bed filters may lead
the particles to form a cake layer on the top portion of the media
bed and may also block the media bed filter. Thus, the maintenance
of such media bed filters needs to be made on a regular basis for
reducing formation of cakes with the media bed. For example, is
FIG. 1A, the raw liquid flow which enters the tank follows a
laminar flow (i.e., without or with reduced turbulence areas).
[0012] Many filters are already known in many applications, such
as, without limitation, chilled and hot water loops, condensate
return, cooling tower make up, iron removal, ion exchange resin
pre-filtration, membrane pre-filtration, potable water and beverage
filtration, process rinse water, process water intake, water reuse,
welder water loops and the like.
[0013] Moreover, traditional filters will require coagulants or
polymers to improve their efficiency towards smaller particles.
Existing vortex filters have the disadvantage of having poor
backwash efficiency, resulting in higher water consumption,
wastewater and important energy costs.
[0014] Traditional vortex filters do not allow good backwash
efficiency and are prompt to short-circuiting even when clean. In
fact, the single injector located at a significant distance from
the apex of the tank creates a significant distortion of the fine
sand surface (FIG. 1B) (i.e., also called microsand or ultrafine
sand) with one side of the media bed being significantly deeper
than its opposite side creating a significant slope in the
filtering media of about 30 to about 40.degree.. This slope creates
a distortion in the hydraulic distribution of the fluid at the
surface and in the depth of the media bed. This phenomenon does not
allow the known vortex filter to use efficiently the filtration
surface area. This is especially true for filters of larger surface
such as 30 inches of diameter and above. As for the backwash
process, the typical single injector, located at a significant
distance from the apex of the tank, does not allow for a good
capture of the particles (or fine particles) to be removed as this
design does not allow for a plug flow removal process. It is to be
noted that the configuration as shown in FIG. 1B would not result
in a good hydraulic flow. The media bed, and more particularly the
filtering media is significantly deformed by the water flow which
enters the tank at a significant distance from the apex of the
tank.
[0015] Furthermore, open-tank media bed filters include a raw
liquid flow inlet which is configured so to lead the water gently
above the filtering media so that the particles flow gently within
the filtering media, and the filtering media surface is not in
motion nor disturbed.
[0016] There is therefore a need for improved media bed filters for
filtering and backwashing fine particles from a raw liquid flow and
for methods of using the same.
SUMMARY
[0017] According to an embodiment, there is provided a media bed
filter for filtering fine particles from a raw liquid flow, the
media bed filter comprising: a tank having: a top portion; a bottom
portion defining a bottom surface for receiving a media bed, the
media bed having a supporting media to be disposed on the bottom
surface and a filtering media for covering the supporting media,
the top portion of the tank being above the filtering media of the
media bed; a raw liquid inlet in fluid communication with a nozzle
configuration located in the top portion of the tank for providing
the raw liquid flow in the tank in the form of a plurality of jets
at a directional velocity substantially equal or greater to a
disengagement velocity of the filtering media.
[0018] According to another embodiment, the nozzle configuration
comprises a plurality of nozzles, each one of the plurality of
nozzles for providing the raw liquid flow in the tank in the form
of a respective one of the plurality of jets at the directional
velocity towards the filtering media.
[0019] According to a further embodiment, the plurality of nozzles
is oriented in opposite directions.
[0020] According to yet another embodiment, the top portion of the
tank defines a top portion surface and further wherein the nozzle
configuration is oriented for providing the plurality of jets
towards the top portion surface of the tank, thereby providing the
raw liquid flow in the tank at a parallel velocity substantially
equal or greater to the disengagement velocity of the filtering
media.
[0021] According to another embodiment, the nozzle configuration is
one of: located above the raw liquid inlet within the top portion
of the tank and located below the raw liquid inlet within the top
portion of the tank.
[0022] According to a further embodiment, the nozzle configuration
is oriented for providing the plurality of jets perpendicularly
towards the filtering media of the media bed.
[0023] According to yet another embodiment, the media bed filter
further comprises a baffle located in the top portion of the tank
and between the nozzle configuration and the filtering media.
[0024] According to another embodiment, the baffle is located
substantially above the filtering media, thereby providing the raw
liquid flow in the tank at a parallel velocity substantially equal
or greater to the disengagement velocity of the filtering
media.
[0025] According to a further embodiment, the raw liquid inlet
comprises a plurality of raw liquid inlets, each one of the
plurality of raw liquid inlets being in fluid communication with a
respective nozzle configuration.
[0026] According to yet another embodiment, the nozzle
configuration is one of: oriented in an upward direction for
providing the plurality of jets to enter the tank in an upwardly
direction and oriented in a downwardly direction for providing the
plurality of jets to enter the tank in a downwardly direction.
[0027] According to another embodiment, the nozzle configuration is
oriented for providing the plurality of jets horizontally towards
the filtering media of the media bed, the nozzle configuration
being located in the top portion of the tank at substantially the
same level of the filtering media.
[0028] According to a further embodiment, each one of the plurality
of nozzles defines a shape comprising at least one of: an
elbow-like shape, a straight-like shape, a curved-like shape, a
regular polygonal-like shape, a segmented-like shape, an irregular
polygonal-like shape, a circular-like shape, an angular-like shape
and any combination thereof.
[0029] According to yet another embodiment, the media bed filter of
claim 1, further comprising a baffle within the top portion of the
tank for receiving the plurality of jets, thereby providing the raw
liquid flow in the tank at a parallel velocity substantially equal
or greater to the disengagement velocity of the filtering
media.
[0030] According to another embodiment, the baffle comprises a
plurality of baffles, each one of the plurality of baffles being
located substantially above the filtering media, parallel and
laterally distant from another one of the plurality of baffles.
[0031] According to a further embodiment, the plurality of baffles
comprises displaceable baffles.
[0032] According to another embodiment, there is provided a method
for filtering fine particles from a raw liquid flow in a tank
supporting a filtering media, the tank having a top portion, the
method comprising the steps of: receiving the raw liquid flow with
fine particles; and providing the raw liquid flow in the top
portion of the tank in the form of a plurality of jets at a
directional velocity substantially equal or greater to a
disengagement velocity of the filtering media.
[0033] According to a further embodiment, the providing the raw
liquid flow in the top portion of the tank in the form of a
plurality of jets comprises providing the raw liquid flow in the
top portion of the tank in the form of a plurality of jets oriented
in opposite directions, thereby providing the raw liquid flow in
the tank at a parallel velocity substantially equal or greater to
the disengagement velocity of the filtering media.
[0034] According to yet another embodiment, the providing the raw
liquid flow in the top portion of the tank in the form of a
plurality of jets comprises providing the raw liquid flow in the
top portion of the tank in the form of a plurality of jets towards
a top portion surface of the tank, thereby providing the raw liquid
flow in the tank at a parallel velocity substantially equal or
greater to the disengagement velocity of the filtering media.
[0035] According to another embodiment, the providing the raw
liquid flow in the top portion of the tank in the form of a
plurality of jets comprises providing the plurality of jets
perpendicularly towards the filtering media of the media bed.
[0036] According to a further embodiment, the providing the raw
liquid flow in the top portion of the tank in the form of a
plurality of jets comprises providing the raw liquid flow in the
top portion of the tank in the form of a plurality of jets at
substantially the same level of the filtering media, thereby
providing the raw liquid flow in the tank at a parallel velocity
substantially equal or greater to the disengagement velocity of the
filtering media.
[0037] The following terms are defined below.
[0038] The term "top portion of the tank" is intended to mean the
portion defined by the tank which is above the filtering media of
the media bed.
[0039] The term "bottom portion of the tank" is intended to mean
the portion defined by the tank from the bottom surface of the tank
to the filtering media of the media bed.
[0040] The term "filtering media" is intended to mean the fine
granular filtering media covering the supporting media and/or in
movement inside the tank and above the media bed.
[0041] The term "fine particle" is intended to mean the particles
in the raw liquid flow to be filtered by the media bed filter.
[0042] The term "media bed" is intended to mean a bed which
includes the filtering media of the media bed filter which covers
the supporting media and the supporting media.
[0043] The term "supporting media" is intended to mean a portion of
the supporting media bed which supports the filtering media of the
media bed filter or which is covered by the filtering media of the
media bed. The supporting media may be a rigid bottom compact
media, such as a metallic supporting bed with openings or the
supporting media may include a plurality of layers of granular
materials including, without limitations rock, sand, river sand
and/or rocks, and the like. The "supporting media" may also include
a false floor to be installed above the bottom surface of the
tank.
[0044] The term "nozzle configuration" is intended to mean an end
portion of the raw liquid inlet which is located in the top portion
the tank and which forms a plurality of jets to enter the tank. The
nozzle configuration may include a plurality of nozzles. The nozzle
configuration may allow the plurality of jets to circulate towards
a top portion surface of the tank, towards the filtering media of
the media bed and/or towards a baffle which is located in the tank
(or the like).
[0045] Features and advantages of the subject matter hereof will
become more apparent in light of the following detailed description
of selected embodiments, as illustrated in the accompanying
figures. As will be realized, the subject matter disclosed and
claimed is capable of modifications in various respects, all
without departing from the scope of the claims. Accordingly, the
drawings and the description are to be regarded as illustrative in
nature, and not as restrictive and the full scope of the subject
matter is set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Further features and advantages of the present disclosure
will become apparent from the following detailed description, taken
in combination with the appended drawings, in which:
[0047] FIG. 1A illustrates the media bed of a sand filter in
accordance with the prior art;
[0048] FIG. 1B illustrates the media bed of a sand filter in
accordance with the prior art;
[0049] FIG. 1C illustrates a sand filter in accordance with the
prior art which includes one and only one raw liquid inlet located
in the top portion of the tank;
[0050] FIG. 1D illustrates a sand filter in accordance with the
prior art which includes one and only one raw liquid inlet located
in the top portion of the tank;
[0051] FIG. 1E illustrates a top view of the sand filter of FIG.
1C;
[0052] FIG. 2A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with an embodiment;
[0053] FIG. 2B is another perspective view of the media bed filter
of FIG. 2A;
[0054] FIG. 2C is a top plan view of the media bed filter of FIG.
2A;
[0055] FIG. 2D is a side elevation view of the media bed filter of
FIG. 2A;
[0056] FIG. 3A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0057] FIG. 3B is another perspective view of the media bed filter
of FIG. 3A;
[0058] FIG. 3C is an elevation view of the media bed filter of FIG.
3A;
[0059] FIG. 3D is a top plan view of the media bed filter of FIG.
3A;
[0060] FIG. 4A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0061] FIG. 4B is another perspective view of the media bed filter
of FIG. 4A;
[0062] FIG. 4C is an elevation view of the media bed filter of FIG.
4A;
[0063] FIG. 4D is a top plan view of the media bed filter of FIG.
4A;
[0064] FIG. 5A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0065] FIG. 5B is another perspective view of the media bed filter
of FIG. 5A;
[0066] FIG. 5C is an elevation view of the media bed filter of FIG.
5A;
[0067] FIG. 5D is a top plan view of the media bed filter of FIG.
5A;
[0068] FIG. 6A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0069] FIG. 6B is another perspective view of the media bed filter
of FIG. 6A;
[0070] FIG. 6C is an elevation view of the media bed filter of FIG.
6A;
[0071] FIG. 6D is a top plan view of the media bed filter of FIG.
6A;
[0072] FIG. 7A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0073] FIG. 7B is another perspective view of the media bed filter
of FIG. 7A;
[0074] FIG. 7C is an elevation view of the media bed filter of FIG.
7A;
[0075] FIG. 7D is another elevation view of the media bed filter of
FIG. 7A;
[0076] FIG. 7E is a side elevation view of the media bed filter of
FIG. 7A;
[0077] FIG. 8 is a side elevation view of a media bed filter for
filtering fine particles from a raw liquid flow in accordance with
another embodiment;
[0078] FIG. 9 is a side view of a media bed filter for filtering
fine particles from a raw liquid flow showing the supporting media
bed as a rigid bed with openings in accordance with another
embodiment;
[0079] FIG. 10 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0080] FIG. 11 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0081] FIG. 12A is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0082] FIG. 12B is a top plan view of the media bed filter of FIG.
12A;
[0083] FIG. 12C is a side plan view of the media bed filter of FIG.
12A;
[0084] FIG. 13 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment;
[0085] FIG. 14 is a perspective view of a media bed filter for
filtering fine particles from a raw liquid flow in accordance with
another embodiment, where the tank is an open-tank;
[0086] FIG. 15 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment, where the tank is an
open-tank;
[0087] FIG. 16 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment, where the tank is an
open-tank
[0088] FIG. 17 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment, where the tank is an
open-tank
[0089] FIG. 18 is a schematic perspective view of a media bed
filter for filtering fine particles from a raw liquid flow in
accordance with another embodiment, where the tank is an
open-tank;
[0090] FIG. 19 is a schematic elevation view of a nozzle
configuration of a media bed filter for filtering fine particles
from a raw liquid flow in accordance with another embodiment;
[0091] FIG. 20 is a schematic elevation view of a nozzle
configuration of a media bed filter for filtering fine particles
from a raw liquid flow in accordance with another embodiment;
[0092] FIG. 21 is a graph showing elution for a media bed filter
which includes four nozzles in accordance with another embodiment
compared with a media bed filter system which includes one and only
one nozzle; and
[0093] FIG. 22 is a graph which illustrates flow speeds (cm/s) of
particles of the filtering media according to the diameter of these
particles in accordance with another embodiment.
[0094] It will be noted that throughout the appended drawings, like
features are identified by like reference numerals.
DETAILED DESCRIPTION
[0095] In embodiments, there are disclosed media bed filters for
filtering fine particles from a raw liquid flow and method of
filtering fine particles from a raw liquid flow.
[0096] Referring now to the drawings and more particularly from
FIGS. 2A-20, there is shown media bed filters 10 for filtering fine
particles (not shown) from a raw liquid flow. The media bed filters
10 each includes a tank 16 which has a top portion 18 and a bottom
portion 20. The bottom portion 20 defines a bottom surface 22 for
receiving a media bed 24. The media bed 24 includes a supporting
media 28 to be disposed on the bottom surface 22 and a filtering
media 26 for covering the supporting media 28. It is to be noted,
as described above, that the top portion 18 of the tank 16 is being
above the filtering media 26 of the media bed 24. The media bed
filter 10 further includes a raw liquid inlet 30 in fluid
communication with a nozzle configuration 32 which is located in
the top portion 18 of the tank 16. The nozzle configuration 32
provides the raw liquid flow in the tank 16 in the form of a
plurality of jets (not shown) at a directional velocity
substantially equal or greater to a disengagement velocity of the
filtering media 26.
[0097] Referring now to FIGS. 4A-4D, 5A-5D, 10, 11, 12A-12C, 13,
15, 16, 17, 18, 19 and 20, there is shown that the nozzle
configuration 32 comprises a plurality of nozzles 33, where each
one of the plurality of nozzles 33 is for providing the raw liquid
flow in the tank 16 in the form of a respective one of the
plurality of jets at the directional velocity towards the filtering
media 26.
[0098] Referring now to FIGS. 4A-4D, 5A-5D, 10, 11, 12A-12C, 13,
16, 17, 18, 19 and 20, there is shown that the plurality of nozzles
33 of the media bed filter 10 are oriented in opposite
directions.
[0099] Referring now to FIGS. 2A-2D, 4A-4D, 5A-5D, 6A-6D, 8, 10,
11, 12A-12C and 13), there is shown that the top portion 18 of the
tank 16 defines a top portion surface 19 and that the nozzle
configuration 32 is oriented for providing the plurality of jets
towards the top portion surface 19 of the tank 16. This nozzle
configuration 32 provides the raw liquid flow in the tank 16 at a
parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26.
[0100] Referring now to FIGS. 2A-2D, 3A-3D, 4A-4D, 5A-5D, 6A-6D, 8,
9, 10, 11, 13, and 15-20, there is shown that the nozzle
configuration 32 is located above the raw liquid inlet 30 within
the top portion 18 of the tank 16 (FIGS. 10 and 13) or located
below the raw liquid inlet 30 within the top portion 18 of the tank
16 (FIGS. 2A-2D, 3A-3D, 4A-4D, 5A-5D, 6A-6D, 8, 9, 11 and
15-20).
[0101] Referring now to FIGS. 3A-3D, there is shown that the nozzle
configuration 32 of the media bed filter 10 is oriented for
providing the plurality of jets perpendicularly towards the
filtering media 26 of the media bed 24.
[0102] Referring now to FIGS. 19-20, the media bed filter 10
includes a baffle 90 located in the top portion 18 of the tank 16
and between the nozzle configuration 32 and the filtering media 26.
More particularly, the baffle 90 is located substantially above the
filtering media 26. This configuration of the nozzle configuration
32 and the baffle 90 provides the raw liquid flow to enter the tank
16 at a parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26.
[0103] Referring now to FIGS. 2A-2D, 3A-3D, 6A-6D, 8 and 9, there
is shown that the media bed filter 10 includes a plurality of raw
liquid inlets 30. Each one of the plurality of raw liquid inlets 30
is in fluid communication with a respective nozzle configuration
32.
[0104] Referring now to FIGS. 3A-3D, 4A-4D, 5A-5D and 9, there is
shown that the nozzle configuration 32 of the media bed filter 10
is oriented in an upward direction for providing the plurality of
jets to enter the tank 16 in an upwardly direction and/or oriented
in a downwardly direction for providing the plurality of jets to
enter the tank 16 in a downwardly direction (FIGS. 3A-3D, 4A-4D,
5A-5D and 9).
[0105] Referring now to FIGS. 6A-6D, 7A-7E and 15-20, there is
shown that the nozzle configuration 32 of the media bed filter 10
is oriented for providing the plurality of jets horizontally
towards the filtering media 26 of the media bed 24. Indeed, the
nozzle configuration 32 is located in the top portion 18 of the
tank 16 at substantially the same level of the filtering media
26.
[0106] According to an embodiment, the nozzles 33 may define a
shape which includes at least one of, without limitation, an
elbow-like shape, a straight-like shape, a curved-like shape, a
regular polygonal-like shape, a segmented-like shape, an irregular
polygonal-like shape, a circular-like shape, an angular-like shape,
any combination and the like.
[0107] Referring now to FIGS. 9, 14, 19 and 20, there is shown that
the media bed filter 10 includes one or more baffles 90 within the
top portion 18 of the tank 16 for receiving the plurality of jets.
The configuration of the baffle(s) 90 and of the nozzle
configuration 32 thereby provides the raw liquid flow in the tank
16 at a parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26. As shown in FIG.
14, the baffles 90 of the media bed filter 10 are located
substantially above the filtering media 26, parallel and laterally
distant from each other. Moreover, the plurality of baffles 90
(FIG. 14) are displaceable baffles (i.e., electrically
displaceable).
[0108] More particularly and according to an embodiment, FIGS.
2A-2D show a media bed filter 10 which includes two raw liquid
inlets 30. Each one of the raw liquid inlets 30 is in fluid
communication with a respective nozzle configuration 32. The nozzle
configurations 32 are oriented in the same direction and
substantially towards the top portion surface 19 of the tank 16.
This configuration may allow the plurality of jets to circulate
towards the top portion surface 19 of the tank 16, then to
circulate along the top portion surface 19, which thereby allows at
least a portion of the plurality of jets to circulate at a parallel
velocity substantially equal or greater to the disengagement
velocity of the filtering media 24. The nozzles 33 define a
curved-like shape for allowing the raw liquid flow to circulate
towards the top portion surface 19.
[0109] According to another embodiment, FIGS. 3A-3D show a media
bed filter 10 which includes four raw liquid inlets 30. Each one of
the raw liquid inlets 30 is in fluid communication with a
respective nozzle configuration 32. The nozzle configurations 30
are oriented in the same direction and substantially towards the
filtering media 26 of the tank 16 at a specific distance (i.e., a
distance such that the plurality of jets will not dig into the
filtering media 26) from the filtering media 26. This configuration
may allow the plurality of jets to circulate towards the filtering
media 26 of the tank 16, which thereby allows at least a portion of
the plurality of jets to circulate at a parallel velocity
substantially equal or greater to the disengagement velocity of the
filtering media 26. The nozzles 33 define a straight-like shape for
allowing the raw liquid flow to circulate towards the filtering
media 26.
[0110] According to another embodiment, FIGS. 4A-4D show a media
bed filter 10 which includes one raw liquid inlet 30. The raw
liquid inlet 30 is in fluid communication with a respective nozzle
configuration 32. The nozzle configuration 32 includes three
nozzles 33 which are oriented in opposite directions and
substantially towards the top portion surface 19 of the tank 16.
This configuration may allow the plurality of jets to circulate
towards the top portion surface 19 of the tank 16, then to
circulate along the top portion surface 19, which thereby allows at
least a portion of the plurality of jets to circulate at a parallel
velocity substantially equal or greater to the disengagement
velocity of the filtering media 26. Since the nozzles 33 are
substantially at the same level of the filtering media 26, this
configuration may also allow the plurality of jets to circulate at
a parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26 when they exit the
nozzles 33. The nozzles 33 define an angular-like shape for
allowing the raw liquid flow to circulate towards the top portion
surface 19 and/or the filtering media 26.
[0111] According to another embodiment, FIGS. 5A-5D show a media
bed filter 10 which includes one raw liquid inlet 30. The raw
liquid inlet 30 is in fluid communication with a respective nozzle
configuration 32. The nozzle configuration 32 includes two nozzles
33 which are oriented in opposite directions and substantially
towards the top portion surface 19 of the tank 16. This
configuration may allow the plurality of jets to circulate towards
the top portion surface 19 of the tank 16, then to circulate along
the top portion surface 19, which thereby allows at least a portion
of the plurality of jets to circulate at a parallel velocity
substantially equal or greater to the disengagement velocity of the
filtering media 26. Since the nozzles 33 are substantially at the
same level of the filtering media 26, this configuration may also
allow the plurality of jets to circulate at a parallel velocity
substantially equal or greater to the disengagement velocity of the
filtering media 26 when they exit the nozzles 33. The nozzles 33
define an angular-like shape for allowing the raw liquid flow to
circulate towards the top portion surface 19 and/or the filtering
media 26.
[0112] According to another embodiment, FIGS. 6A-6D show a media
bed filter 10 which includes a plurality of raw liquid inlets 30.
The raw liquid inlets 30 are in fluid communication with a
respective nozzle configuration 32. The nozzle configurations 32
are oriented in a direction such that it allows the raw liquid flow
to circulate within a tank 16 having a donough-like shape. The
nozzle configurations 32 are also substantially oriented towards
the top portion surface 19 of the tank 16. This configuration may
allow the plurality of jets to circulate towards the top portion
surface 19 of the tank 16, then to circulate along the top portion
surface 19, which thereby allows at least a portion of the
plurality of jets to circulate at a parallel velocity substantially
equal or greater to the disengagement velocity of the filtering
media 26. Since the nozzle configurations 32 are substantially at
the same level of the filtering media 26, this configuration may
also allow the plurality of jets to circulate at a parallel
velocity substantially equal or greater to the disengagement
velocity of the filtering media 26 when they exit the nozzle
configurations 32. The nozzles 33 define a straight-like shape for
allowing the raw liquid flow to circulate towards the top portion
surface 19 and/or the filtering media 26.
[0113] According to another embodiment, FIGS. 7A-7E show a media
bed filter 10 which includes one raw liquid inlet 30. The raw
liquid inlet 30 is in fluid communication with a respective nozzle
configuration 32. Since the nozzle configuration 32 is
substantially at the same level of the filtering media 26, this
configuration may also allow the plurality of jets to circulate at
a parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26 when they exit the
nozzle configuration 32. The nozzles 33 define a straight-like
shape for allowing the raw liquid flow to circulate along the
filtering media 26. It is to be noted that the filtering media 26
that is utilized in this filtering media filter 10 may be recycled
via an adapted piping system. It is to be noted that on FIG. 7B,
there is shown that the filtering media 26 adopts a longitudinal
movement in the tank 16. The filtering media 26 (i.e., micro sand)
may be recuperated at the end of the tank 16 via a hydraulic
mechanism or a mechanic mechanism (not shown). Thus, the filtering
media 26 is brought back to another filtering media inlet.
[0114] According to another embodiment, FIG. 8 shows a media bed
filter 10 which includes two raw liquid inlets 30. The raw liquid
inlets 30 are in fluid communication with a respective nozzle
configuration 32. The nozzle configurations 32 are oriented in
opposite directions and substantially towards the top portion
surface 19 of the tank 16. This configuration may allow the
plurality of jets to circulate towards the top portion surface 19
of the tank 16, then to circulate along the top portion surface 19,
which thereby allows at least a portion of the plurality of jets to
circulate at a parallel velocity substantially equal or greater to
the disengagement velocity of the filtering media 26. The nozzles
define an angular-like shape for allowing the raw liquid flow to
circulate towards the top portion surface 19 and/or the filtering
media 26.
[0115] According to another embodiment, FIG. 9 shows a media bed
filter 10 which includes two raw liquid inlets 30. The raw liquid
inlets 30 are in fluid communication with a respective nozzle
configuration 32. The nozzle configurations 32 are oriented in
opposite directions and substantially towards the top portion
surface 19 of the tank 16. This configuration may allow the
plurality of jets to circulate towards the top portion surface 19
of the tank, then to circulate along the top portion surface 19,
which thereby allows at least a portion of the plurality of jets to
circulate at a parallel velocity substantially equal or greater to
the disengagement velocity of the filtering media 26. The nozzles
33 define an angular-like shape for allowing the raw liquid flow to
circulate towards the top portion surface 19 and/or the filtering
media 26. The media bed filter 10 of FIG. 9 also includes two
baffles 90 for allowing the filtering media 26 to move in an
optimized manner for allowing filtration of the fine particles and
venturi portions 80 around at least a portion of the nozzle
configurations 32. The venturi portions 80 may recycle the
filtering media faster and/or more efficiently (i.e., the venturi
portions 80 may optimize recycling of the filtering media 26).
[0116] In FIG. 9, the supporting media 28 is a rigid supporting
layer defining openings (i.e., such as a false floor).
[0117] According to another embodiment, FIGS. 10 and 11 shows media
bed filters 10 which includes one raw liquid inlet 30. The raw
liquid inlet 30 is in fluid communication with a respective nozzle
configuration 32. The nozzle configuration 32 includes four
upwardly (FIG. 10) or downwardly (FIG. 11) oriented nozzles 33
which are oriented in opposite directions and substantially towards
the top portion surface 19 of the tank 16. This configuration may
allow the plurality of jets to circulate towards the top portion
surface 19 of the tank 16, then to circulate along the top portion
surface 19, which thereby allows at least a portion of the
plurality of jets to circulate at a parallel velocity substantially
equal or greater to the disengagement velocity of the filtering
media 26. The nozzles 33 define a straight-like shape for allowing
the raw liquid flow to circulate towards the top portion surface 19
and/or the filtering media 26. Additionally, since the nozzle
configuration 33 is substantially at the same level of the
filtering media 26, this configuration may also allow the plurality
of jets to circulate at a parallel velocity substantially equal or
greater to the disengagement velocity of the filtering media 26
when they exit the nozzle configuration 32.
[0118] According to another embodiment, FIGS. 12A-12C show a media
bed filter 10 which includes one raw liquid inlet 30. The raw
liquid inlet 30 is in fluid communication with a respective nozzle
configuration 32. The nozzle configuration 32 includes two nozzles
33 which are oriented in opposite directions and substantially
towards the top portion surface 19 of the tank 16. This
configuration may allow the plurality of jets to circulate towards
the top portion surface 19 of the tank 16, then to circulate along
the top portion surface 19, which thereby allows at least a portion
of the plurality of jets to circulate at a parallel velocity
substantially equal or greater to the disengagement velocity of the
filtering media 26. The nozzles 33 define a straight-like shape for
allowing the raw liquid flow to circulate towards the top portion
surface 19 and/or the filtering media 26.
[0119] According to another embodiment, FIG. 13 shows a media bed
filter 10 which includes one raw liquid inlet 30. The raw liquid
inlet 30 is in fluid communication with a respective nozzle
configuration 32. The nozzle configuration 32 includes two upwardly
oriented nozzles 33 which are oriented in opposite directions and
substantially towards the top portion surface 19 of the tank 16.
This configuration may allow the plurality of jets to circulate
towards the top portion surface 19 of the tank 16, then to
circulate along the top portion surface 19, which thereby allows at
least a portion of the plurality of jets to circulate at a parallel
velocity substantially equal or greater to the disengagement
velocity of the filtering media 26. The nozzles 33 define a
straight-like shape for allowing the raw liquid flow to circulate
towards the top portion surface 19 and/or the filtering media
26.
[0120] According to another embodiment, FIG. 14 shows a media bed
filter 10 which includes an opened tank 16. The media bed filter 10
includes one raw liquid inlet 30. The raw liquid inlet 30 is in
fluid communication with a respective nozzle configuration 32. The
nozzle configuration 32 is oriented substantially towards the top
portion surface 19 of the tank 16. The media bed filter 10 further
includes a plurality of baffles 90. Each one of the plurality of
baffles 90 are located substantially above the filtering media 26,
parallel, and laterally distant from each other. This configuration
may allow the plurality of jets to circulate towards the baffles 90
of the tank 16, then to circulate along the baffle walls 91, which
thereby allows at least a portion of the plurality of jets to
circulate at a parallel velocity substantially equal or greater to
the disengagement velocity of the filtering media 26.
[0121] According to other embodiments, FIGS. 15-18 show media bed
filters 10 which include one raw liquid inlet 30. The raw liquid
inlet 30 is in fluid communication with a plurality of nozzle
configurations 32. In FIG. 15, the nozzles 33 are oriented in the
same direction and substantially at the same level of the filtering
media 26. This configuration may also allow the plurality of jets
to circulate at a parallel velocity substantially equal or greater
to the disengagement velocity of the filtering media 26 when they
exit the nozzles 33. In FIGS. 16-18, the nozzles 33 are oriented in
opposite directions and substantially at the same level of the
filtering media 26. This configuration may also allow the plurality
of jets to circulate at a parallel velocity substantially equal or
greater to the disengagement velocity of the filtering media 26
when they exit the nozzles 33. As further shown in FIG. 15, the
nozzles 33 are proximate to the filtering media 26. As shown in
FIG. 16, the nozzles 33 are proximate to the filtering media 26 and
are arranged in the middle of the tank 16 such as to allow the
plurality of jets to circulate towards opposite directions. As
shown in FIG. 17, the nozzles 33 are proximate to the filtering
media 26 and are arranged in the middle of the tank 16 and along
the length of the tank 16 such as to allow the plurality of jets to
circulate towards opposite directions and along the length of the
tank 16. As shown in FIG. 18, the nozzles 33 are proximate to the
filtering media 26 and are arranged in the middle of the tank 16
such as to allow the plurality of jets to circulate towards a
plurality of directions (i.e., the nozzle configurations 32
includes circular nozzles 33).
[0122] Referring now to FIGS. 19-20, the media bed filter includes
a baffle 90 located in the top portion of the tank and between the
nozzle configuration 32 and the filtering media 26. More
particularly, the baffle 90 is located substantially above the
filtering media 26 for providing the raw liquid flow in the tank 16
at a parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26.
[0123] It is to be noted that the filter media filter 10 as
described above includes one or a plurality of a filtered liquid
outlets 34. The filtered liquid outlets 34 are located in proximity
to the bottom portion 20 of the tank 16 and allow a filtered liquid
flow to exit the tank 16. The media bed filter 10 may further
include at least one backwash liquid outlet 99 which is located in
the top portion 18 of the tank 16 for removing the fines particles
from the tank 16 during a backwash sequence. It is to be mentioned
that the backwash liquid outlet 99 and the raw liquid inlet 30 may
be the same for allowing the raw liquid inlets 30 to provide the
plurality of jets in the tank 16 and also to remove the fine
particles from the tank 16 during the backwash sequence (FIGS.
2A-2D, 3A-3D, 4A-4D, 5A-5B, 6A-6B, 8, 9, 10, 12A-12B and 13).
[0124] According to another embodiment, there is provided a method
for filtering fine particles from a raw liquid flow in a tank 16
supporting a filtering media 26. The method includes the steps of
1--receiving the raw liquid flow with fine particles; and
2--providing the raw liquid flow in the top portion 18 of the tank
16 in the form of a plurality of jets at a directional velocity
substantially equal or greater to a disengagement velocity of the
filtering media 26.
[0125] According to another embodiment, the step of providing the
raw liquid flow in the top portion 18 of the tank 16 in the form of
a plurality of jets comprises the step of providing the raw liquid
flow in the top portion 18 of the tank 16 in the form of a
plurality of jets oriented in opposite directions, thereby
providing the raw liquid flow in the tank 16 at a parallel velocity
substantially equal or greater to the disengagement velocity of the
filtering media 26.
[0126] According to another embodiment, the step of the providing
the raw liquid flow in the top portion 18 of the tank 16 in the
form of a plurality of jets comprises the step of providing the raw
liquid flow in the top portion 18 of the tank 16 in the form of a
plurality of jets towards a top portion surface 19 of the tank 16,
thereby providing the raw liquid flow in the tank 16 at a parallel
velocity substantially equal or greater to the disengagement
velocity of the filtering media 26.
[0127] According to another embodiment, the step of providing the
raw liquid flow in the top portion 18 of the tank 16 in the form of
a plurality of jets comprises the step of providing the plurality
of jets perpendicularly towards the filtering media 26 of the media
bed 24.
[0128] According to a further embodiment, the step of the providing
the raw liquid flow in the top portion 18 of the tank 16 in the
form of a plurality of jets comprises the step of providing the raw
liquid flow in the top portion 18 of the tank 16 in the form of a
plurality of jets at substantially the same level of the filtering
media 26, thereby providing the raw liquid flow in the tank 16 at a
parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26.
[0129] It is also to be noted that these configurations of the
media bed filters 10 may provide a surface filtration which keeps
the fine particles above the filtering media 26 of the media bed 24
without exposing the supporting media 28. It is to be noted that
the filtering media 26 is returning more rapidly towards the bottom
portion 20 of the tank 16 than the fine particles themselves for
allowing an optimized filtration of the raw liquid flow and to
allow suspension of the fine particles to facilitate their removal.
The media bed filters 10 as described above further allow a
suspension of a part of the fine particles which are removed from
the tank 16 during the backwash sequence.
[0130] According to an embodiment, the media bed 24 may include a
supporting media 28 at the bottom surface 22 of the tank 16 for
supporting the filtering media 26. It is to be noted that the
supporting media 28 is below the filtering media 26. Additionally,
the filtering media 26 and the supporting media 28 may each
comprise an aggregate material. The aggregate material may be
included in the group consisting of, without limitation, a rock
material, a mesh particles material, a sand material, a course sand
material, a fine sand material, a river sand, a garnet material
(i.e., density of 4 for example), any combination of material and
the like. It is to be noted that the sphericity of the filtering
media 26 and of the supporting media 28 may be important for
providing an improved filtration of the fine particles within the
raw liquid flow. The supporting media 28 may include a plurality of
supporting media layers (not shown). The plurality of supporting
media layers is disposed in layers from the bottom surface 22 of
the tank 16 and with the coarser supporting media layer at the
bottom surface 22 of the tank 16. For example, a supporting media
layer having a smaller diameter would be layered above another
supporting media layer having a wider diameter. The filtering media
26 of the media bed 24 may comprise 0.15 mm silica sand (effective
size). For example, the media bed filter 10 may include two
supporting media layers of different materials.
[0131] It is to be noted that the media bed filter 10 may filter
fine particles down to submicron (about 0.25 micron-1 micron) and
keep them above the media bed 24 (i.e., at least in part) and in
the tank 16. It is also to be noted that the media bed filter 10
may use fine media (i.e., or granular media) less than 0.3 mm for
allowing filtering particles down to less than one micron, 0.5
microns for example.
[0132] According to an embodiment, the tank 16 may define a
vertical axis, an horizontal axis, a combination of axis or any
other axis. Also, the tank 16 may define one of, without
limitation, a spherical shape, a cylindrical shape, a prismatic
shape, a regular polygonal prismatic shape, an irregular polygonal
prismatic shape, an open tank shape, a doughnut-like shape, any
combination, and the like.
[0133] According to another embodiment, the media bed filter 10 may
further include a control unit (not shown) for electrically
controlling one of the velocity of the plurality of jets exiting
the nozzle configurations 32 and the orientation of the nozzle
configurations 32 and the raw liquid inlets 30. It is to be
mentioned that other parameter within or outside the tank 16 may be
controlled via the control unit of the media bed filter 10.
[0134] Most preferably, the raw fluid flow to be filtered is a raw
water flow, but it can be any other raw fluid flow depending on the
application of the filtration. For instance, the media bed filter
10 may be used, without limitations, in chilled and hot water
loops, in condensate return, in cooling tower make up, in iron
removal, in water and wastewater treatment applications, in ion
exchange resin pre-filtration, in membrane pre-filtration, in post
clarifier discharge, in potable water treatments, in beverage
treatments, in process rinse water, in process water intake, water
reuse, welder water loops, and the like.
[0135] According to another embodiment, the velocity and the
disengagement velocity may be in the range of 0.4 to 1.6 ft/s or
greater depending on the disengagement velocity of the utilized
filtering media 26 of the media bed 24.
[0136] The media bed filters 10 described above provide the raw
liquid flow to circulate towards to filtering media 26 at a
parallel velocity substantially equal or greater to the
disengagement velocity of the filtering media 26. As a result, the
filtering media 26 of the media bed 24 can be used without clogging
rapidly the media bed 24, and the filtered fluid flow which may be
largely free of impurities, is then filtered through the media bed
24 and subsequently collected. Contaminants trapped above the media
bed 24 may be removed using an automatic backwash sequence, which
requires less water and a shorter operating time. The backwash time
is therefore half of the normal time. The media bed filters 10 can
remove down to sub-micron levels at 5 times the flow rate of other
media filters, while requiring 50% less water during backwash
sequences.
[0137] It is to be noted that the media bed filters 10 as described
above may provide with a better utilization of the surface area of
the filtering media 26 and with a larger surface of filtration
(i.e., since the nozzle configurations 32 allow the plurality of
jets to circulate at a directional velocity substantially equal or
greater to the disengagement velocity of the filtering media 26).
The flow of raw liquid entering the media bed filter 10 may then be
improved and/or optimized and the slope of the media bed 24 would
be reduced compared to the one created during filtration within a
traditional media bed filter (i.e., a slope having an angle of
about 40.degree. and over for a traditional media bed filter
compared to a slope having an angle of about less than 30.degree.
for the media bed filters 10 as described above).
[0138] The media bed filters (i.e., crossflow media bed filters) as
described above use nozzle configurations (i.e., injector designs)
which sweeps actively the whole surface of the filtering media
(i.e., microsand) for which a portion is put in suspension in the
raw liquid (i.e., water) above the filtering media. The filtering
media (i.e., microsand) settles back on the filtration surface
faster than the fine particles to be removed from the tank of the
media bed filter. This surface sweeping action effect keeps the
surface filtering media from plugging quickly and keeps a portion
of the fine particles to be removed in the water above the
filtering media. The nozzles or injectors are located and designed
within the tank such as to allow for the returning filtering media
(i.e., microsand) to settle back on the surface in an evenly
manner, thereby avoiding the traditional slope found in larger
traditional vortex bed filters. This concept allows for a greater
efficiency and avoids hydraulic short-circuiting in the media bed.
The surface of the filtering media (i.e., microsand) of the media
bed filters as described above has minimal deformation with riddles
at its surface instead of the traditional slope created by the
traditional injector design.
[0139] The present invention will be more readily understood by
referring to the following examples which are given to illustrate
the invention rather than to limit its scope.
Example 1
Surfaces and Angles Depending on the Diameter of the Tank
[0140] The media bed filter may define different angles of the
filtering media depending on their diameter. For example, the angle
of a 30'' tank at its nominal raw water flow and water velocity
injection is 40.degree..
[0141] The media bed filter and method may be applied in different
size and shape of tanks with the numbers of nozzles and media bed
adapted to the tank condition and the filtration area. The media
bed filter has to reflect the water velocity at the filtration
surface. The media bed filter may use a 0.15 mm sand particle
horizontal critic speed at a density of about 2.65 to adjust the
process. The critical speed (i.e., the disengagement velocity), at
the filtration surface for the actual models, are in the range of
0.4 to 1.2 ft/s.
Example 2
Supporting Media Bed for 20'' Tank
[0142] The supporting media bed may consist of several layers
(Media from bags). After installing a layer, it must be leveled and
compacted before to proceed to the next layer: (A bag of 50 lbs.
has a volume of 0.5 ft.sup.3)
Layer 1: 1/2.times.1/4'' Rock, 2 bags 1 ft.sup.3 Layer 2:
1/4.times.1/8'' Rock, 1 bag 0.5 ft.sup.3 Layer 3: 20 mesh (1 mm), 1
bag 0.5 ft.sup.3 Layer 4: Course sand #40 (0.50 mm), 2 bags 1
ft.sup.3 Layer 5: Fine sand #70 (0.15 mm), up to 6'' below the
upper raw liquid inlet, 3 bags 1.5 ft.sup.3
Example 3
TABLE-US-00001 [0143] TABLE 1 Performance of different media bed
filters in relation with the nozzle configuration, the inlet flow
rate and the kaolin concentration 1-2 .mu.m Inlet Outlet average
Injector Freeboard Flow Flow .DELTA.P start .DELTA.P End Kaolin
Dosage Concentration Concentration Removal Configuration (inch)
(gpm) (m.sup.3/h) (psi) (psi) (kg) Type (mg/L) (mg/L) Performance
Prior Art - 1 inj. 7.5 300 68 3 5 1 slug 140 71 49% Prior Art - 1
inj. 7.5 300 68 4 4.5 1 slug 185 77 58% Prior Art - 1 inj. 7.5 300
68 3.5 5 2 slug 319 146 54% Prior Art Traditionnal 7.25 300 68 7.5
9.5 1 slug 186 69 63% 3 7.25 300 68 7 13 8 interval -- -- -- 3 7.25
300 68 7.5 12.5 4 interval -- -- -- 4 down 7.25 300 68 7.5 9 1 slug
224 81 82% 4 down 7.25 300 68 7.5 9.5 1 slug 206 49 76% 4 up 7.25
300 68 8.5 13.5 4 interval -- -- -- 4 up 7.25 300 68 8.25 10.25 1
slug 251 57 77% 4 up 7.25 300 68 8.5 11 2 slug 404 150 63% 4 up
7.25 300 68 7.75 9.25 1 slug 193 69 64% 4 up 7.5 350 79 7 8.5 1
slug 163 55 66% 4 up 7.5 300 68 6 13.5 6 slug 1058 478 55% 4 up 7.5
360 82 8.5 10.5 1.2 slug 250 60 76% 4 up 7.5 360 82 8 10 1 slug 191
37 81% 4 up 7.5 400 91 9 11 1 slug 203 53 74% 4 up 7.5 400 91 10.5
13 1 slug 235 41 83% * Performance of the media bed filter =
(Concentration of fine particles IN - Concentration of fine
particles OUT)/Concentration of fine particles IN
[0144] Referring now to Table 1 above, there is shown that the
performance of a media bed filter is increased when the
configuration of the media bed filter includes four nozzles (i.e.,
4 up) oriented in an upwardly direction within the tank and when
the flow rate is increased (i.e., up to a performance of 83% when
the flow rate reaches 400 gpm) (FIGS. 10 and 11).
[0145] FIG. 21 is a graph showing elution for a media bed filter
which includes four nozzles in accordance with another embodiment
compared with a media bed filter system which includes one and only
one nozzle.
[0146] FIG. 22 is a graph which illustrates flow speeds (cm/s) of
particles of the filtering media according to the diameter of these
particles in accordance with another embodiment. FIG. 18 may be
used to establish the disengagement velocity of the filtering media
which covers the supporting media.
[0147] While preferred embodiments have been described above and
illustrated in the accompanying drawings, it will be evident to
those skilled in the art that modifications may be made without
departing from this disclosure. Such modifications are considered
as possible variants comprised in the scope of the disclosure.
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